简介
本文章使用NodeMCU(ESP8266)开发板和SHTC3温湿度传感器接入阿里云物联网(IoT)平台，并上传读取到的温湿度数据。每秒读取一次温湿度数据，每30秒上传一次30秒内的温湿度的平均值。可以自己修改一下程序使用其他温湿度传感器。本文程序使用Arduino IDE开发。
DHT11和DHT22温湿度传感器数据读取的程序：https://blog.zeruns.tech/archives/527.html
ESP8266开发环境搭建教程：https://blog.zeruns.tech/archives/526.html
SHTC3的SDA引脚接NodeMCU的D5引脚，SCL引脚接NodeMCU的D6引脚。
设置物联网平台
首先注册阿里云账号并开通物联网平台：/product/iot?source=5176.11533457&userCode=jdjc69nf&type=copy
然后打开物联网平台的控制台：https://iot./product
接着按照图片提示创建产品
按照图片提示添加设备
程序源码
需先安装PubSubClient、ArduinoJson、SparkFun SHTC3这三个库。
然后按照下面的教程修改PubSubClient.h
按照代码中文字提示修改参数即可。
#include <ESP8266WiFi.h>/* 依赖 PubSubClient 2.4.0 */#include <PubSubClient.h>/* 依赖 ArduinoJson 5.13.4 */#include <ArduinoJson.h>#include <SparkFun_SHTC3.h>/* 连接您的WIFI SSID和密码 */#define WIFI_SSID "路由器SSID"#define WIFI_PASSWD "密码"/* 设备的三元组信息*/#define PRODUCT_KEY "设备PRODUCT_KEY"#define DEVICE_NAME "替换DEVICE_NAME"#define DEVICE_SECRET"替换DEVICE_SECRET"#define REGION_ID "cn-shanghai"/* 线上环境域名和端口号，不需要改 */#define MQTT_SERVER PRODUCT_KEY ".iot-as-mqtt." REGION_ID "."#define MQTT_PORT 1883#define MQTT_USRNAMEDEVICE_NAME "&" PRODUCT_KEY#define CLIENT_ID "ESP8266|securemode=3,timestamp=1234567890,signmethod=hmacsha1|"// 算法工具: http://iot-face.oss-cn-/tools.htm 进行加密生成password// password教程 /cloud-dev/iot-tech/mebm5g#define MQTT_PASSWD "参考上面password教程，算法工具生成，如果上面的教程看不懂就看文章下面"#define ALINK_BODY_FORMAT "{\"id\":\"ESP8266\",\"version\":\"1.0\",\"method\":\"thing.event.property.post\",\"params\":%s}"#define ALINK_TOPIC_PROP_POST"/sys/" PRODUCT_KEY "/" DEVICE_NAME "/thing/event/property/post"unsigned long lastMs = 0;float RH,T,RH_sum,T_sum;unsigned char count=0;WiFiClient espClient;PubSubClient client(espClient);SHTC3 mySHTC3;void callback(char *topic, byte *payload, unsigned int length){Serial.print("Message arrived [");Serial.print(topic);Serial.print("] ");payload[length] = '\0';Serial.println((char *)payload);}void wifiInit(){WiFi.mode(WIFI_STA);WiFi.begin(WIFI_SSID, WIFI_PASSWD); //连接WiFiwhile (WiFi.status() != WL_CONNECTED){delay(1000);Serial.println("WiFi not Connect");}Serial.println("Connected to AP");Serial.println("IP address: ");Serial.println(WiFi.localIP()); Serial.print("espClient [");client.setServer(MQTT_SERVER, MQTT_PORT); /* 连接WiFi之后，连接MQTT服务器 */client.setCallback(callback);}void mqttCheckConnect(){while (!client.connected()){Serial.println("Connecting to MQTT Server ...");if (client.connect(CLIENT_ID, MQTT_USRNAME, MQTT_PASSWD)){Serial.println("MQTT Connected!");}else{Serial.print("MQTT Connect err:");Serial.println(client.state());delay(5000);}}}void mqttIntervalPost(){char param[32];char jsonBuf[128];sprintf(param, "{\"CurrentTemperature\":%f}",T_sum/count);sprintf(jsonBuf, ALINK_BODY_FORMAT, param);Serial.println(jsonBuf);boolean d = client.publish(ALINK_TOPIC_PROP_POST, jsonBuf);if(d){Serial.println("publish Temperature success"); }else{Serial.println("publish Temperature fail"); }//https://blog.zeruns.tech sprintf(param, "{\"CurrentHumidity\":%f}",RH_sum/count);sprintf(jsonBuf, ALINK_BODY_FORMAT, param);Serial.println(jsonBuf);d = client.publish(ALINK_TOPIC_PROP_POST, jsonBuf);if(d){Serial.println("publish Humidity success"); }else{Serial.println("publish Humidity fail"); }}void errorDecoder(SHTC3_Status_TypeDef message) // The errorDecoder function prints "SHTC3_Status_TypeDef" resultsin a human-friendly way{switch(message){case SHTC3_Status_Nominal : Serial.print("Nominal"); break;case SHTC3_Status_Error : Serial.print("Error"); break;case SHTC3_Status_CRC_Fail : Serial.print("CRC Fail"); break;default : Serial.print("Unknown return code"); break;}}//https://blog.zeruns.techvoid setup() {/* initialize serial for debugging */Serial.begin(115200);Serial.println("Demo Start");wifiInit();Wire.begin(D5,D6); //初始化Wire（IIC）库unsigned char i=0;errorDecoder(mySHTC3.begin());}// the loop function runs over and over again forevervoid loop(){delay(1000); //延时1000毫秒SHTC3_Status_TypeDef result = mySHTC3.update();if(mySHTC3.lastStatus == SHTC3_Status_Nominal) //判断SHTC3状态是否正常{RH = mySHTC3.toPercent(); //读取湿度数据 T = mySHTC3.toDegC(); //读取温度数据RH_sum+=RH;T_sum+=T;count+=1;}else{Serial.print("Update failed, error: ");errorDecoder(mySHTC3.lastStatus); //输出错误原因Serial.println();}Serial.print("Humidity:"); //向串口打印 Humidity:Serial.print(RH); //向串口打印湿度数据Serial.print("%");Serial.print(" Temperature:");Serial.print(T); //向串口打印温度数据Serial.println("C"); Serial.println("https://blog.zeruns.tech");if (millis() - lastMs >= 30000){lastMs = millis();mqttCheckConnect(); /* 上报 */mqttIntervalPost();count=0;RH_sum=0;T_sum=0;}client.loop();}
修改PubSubClient.h
找到PubSubClient.h文件，将#define MQTT_MAX_PACKET_SIZE后的数字改为1024，将#define MQTT_KEEPALIVE后的数字改为60
password生成教程
password生成工具：http://iot-face.oss-cn-/tools.htm
假设你的设备三元组数据如下
设备三元组ProductKey = a14Xib5kdYdDeviceName = ESP8266DeviceSecret = oLyaKqVxtRvjH284LdhqVgVUx1UPy6zq建立MQTT连接时参数，这个信息是代码中的CLIENT_ID，可以自己设置clientId = ESP8266timestamp = 1234567890signmethod = hmacsha1
然后根据这些信息生成password的content
clientIdESP8266deviceNameESP8266productKeya15ptdU1zhPtimestamp1234567890
明文输入content，秘钥输入deviceSecret，点击hmac-sha1就可以生成password
